Categoría: Papers con abstracts

BACKGROUND: Integration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT) called Dual Valence Association Task (DVAT) was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic). METHODS: Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT. RESULTS: Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT. CONCLUSIONS: Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.

Letter regarding Article “Incidence of Stroke and Socioeconomic Neighborhood Characteristics: An Ecological Analysis of Dijon Stroke Registry». Autores Sposato L, Saposnik G. Año 2011 Journal  Sposato L, Saposnik G. Volumen 42(10): 557-558 Abstract   Otra información    

BACKGROUND: Mitochondrial dysfunction and oxidative stress are pathophysiologic mechanisms implicated in experimental models and genetic forms of Parkinson’s disease (PD). Certain pesticides may affect these mechanisms, but no pesticide has been definitively associated with PD in humans. OBJECTIVES: Our goal was to determine whether pesticides that cause mitochondrial dysfunction or oxidative stress are associated with PD or clinical features of parkinsonism in humans. METHODS: We assessed lifetime use of pesticides selected by mechanism in a case-control study nested in the Agricultural Health Study (AHS). PD was diagnosed by movement disorders specialists. Controls were a stratified random sample of all AHS participants frequency-matched to cases by age, sex, and state at approximately three controls:one case. RESULTS: In 110 PD cases and 358 controls, PD was associated with use of a group of pesticides that inhibit mitochondrial complex I [odds ratio (OR)=1.7; 95% confidence interval (CI), 1.0-2.8] including rotenone (OR=2.5; 95% CI, 1.3-4.7) and with use of a group of pesticides that cause oxidative stress (OR = 2.0; 95% CI, 1.2-3.6), including paraquat (OR=2.5; 95% CI, 1.4-4.7). CONCLUSIONS: PD was positively associated with two groups of pesticides defined by mechanisms implicated experimentally-those that impair mitochondrial function and those that increase oxidative stress-supporting a role for these mechanisms in PD pathophysiology.

Letter Regarding Article “Neurocognitive Improvement After Carotid Artery Stenting in Patients With Chronic Internal Carotid Artery Occlusion and Cerebral Ischemia. Autores Sposato L, Gleichgerrcht E, Manes F.  Año 2011 Journal  Sposato L, Gleichgerrcht E, Manes F.  Volumen 43(1): 10-11 Abstract   Otra información    

BACKGROUND: Most of the empirical studies that support the efficacy of prolonged exposure (PE) for treating posttraumatic stress disorder (PTSD) have been conducted on white mainstream English-speaking populations. Although high PTSD rates have been reported for Puerto Ricans, the appropriateness of PE for this population remains unclear. The purpose of this study was to examine the feasibility of providing PE to Spanish speaking Puerto Ricans with PTSD. Particular attention was also focused on identifying challenges faced by clinicians with limited experience in PE. This information is relevant to help inform practice implications for training Spanish-speaking clinicians in PE. RESULTS: Fourteen patients with PTSD were randomly assigned to receive PE (n = 7) or usual care (UC) (n = 7). PE therapy consisted of 15 weekly sessions focused on gradually confronting and emotionally processing distressing trauma-related memories and reminders. Five patients completed PE treatment; all patients attended the 15 sessions available to them. In UC, patients received mental health services available within the health care setting where they were recruited. They also had the option of self-referring to a mental health provider outside the study setting. The Clinician-Administered PTSD Scale (CAPS) was administered at baseline, mid-treatment, and post-treatment to assess PTSD symptom severity. Treatment completers in the PE group demonstrated significantly greater reductions in PTSD symptoms than the UC group. Forty percent of the PE patients showed clinically meaningful reductions in PTSD symptoms from pre- to post-treatment. CONCLUSIONS: PE appears to be viable for treating Puerto Rican Spanish-speaking patients with PTSD. This therapy had good patient acceptability and led to improvements in PTSD symptoms. Attention to the clinicians’ training process contributed strongly to helping them overcome the challenges posed by the intervention and increased their acceptance of PE.

Mental health in Argentina. Autores Moldavsky D, Savage C, Stein E, Blake A.  Año 2011 Journal  Moldavsky D, Savage C, Stein E, Blake A.  Volumen 8(3): 64-66 Abstract   Otra información    

The Implicit Association Test (IAT) is the most popular measure to evaluate implicit attitudes. Nevertheless, its neural correlates are not yet fully understood. We examined event related potentials (ERPs) in response to face- and word processing while indigenous and non-indigenous participants performed an IAT displaying faces (ingroup and outgroup members) and words (positive and negative valence) as targets of category judgments. The N170 component was modulated by valence of words and by ingroup/outgroup face categorization. Contextual effects (face-words implicitly associated in the task) had an influence on the N170 amplitude modulation. On the one hand, in face categorization, right N170 showed differences according to the association between social categories of faces and affective valence of words. On the other, in word categorization, left N170 presented a similar modulation when the task implied a negative-valence associated with ingroup faces. Only indigenous participants showed a significant IAT effect and N170 differences. Our results demonstrate an early ERP blending of stimuli processing with both intergroup and evaluative contexts, suggesting an integration of contextual information related to intergroup attitudes during the early stages of word and face processing. To our knowledge, this is the first report of early ERPs during an ethnicity IAT, opening a new branch of exchange between social neuroscience and social psychology of attitudes.

The most selective disorder of central conceptual knowledge arises in semantic dementia, a degenerative condition associated with bilateral atrophy of the inferior and polar regions of the temporal lobes. Likewise, semantic impairment in both herpes simplex virus encephalitis and Alzheimer’s disease is typically associated with bilateral, anterior temporal pathology. These findings suggest that conceptual representations are supported via an interconnected, bilateral, anterior temporal network and that it may take damage to both sides to produce an unequivocal deficit of central semantic memory. We tested and supported this hypothesis by investigating a case series of 20 patients with unilateral temporal damage (following vascular accident or resection for tumour or epilepsy), utilizing a test battery that is sensitive to semantic impairment in semantic dementia. Only 1/20 of the cases, with a unilateral left lesion, exhibited even a mild impairment on the receptive semantic measures. On the expressive semantic tests of naming and fluency, average performance was worse in the left- than right-unilateral cases, but even in this domain, only one left-lesion case had scores consistently more than two standard deviations below control means. These results fit with recent parallel explorations of semantic function using repetitive transcranial magnetic stimulation as well as functional imaging in stroke aphasic and neurologically intact participants. The evidence suggests that both left and right anterior temporal lobe regions contribute to the representation of semantic memory and together may form a relatively damage-resistant, robust system for this critical aspect of higher cognition.

Visual perception and integration seem to play an essential role in our conscious phenomenology. Relatively local neural processing of reentrant nature may explain several visual integration processes (feature binding or figure–ground segregation, object recognition, inference, competition), even without attention or cognitive control. Based on the above statements, should the neural signatures of visual integration (via reentrant process) be non‐reportable phenomenological qualia? We argue that qualia are not required to understand this perceptual organization.

Neurodynamics of mind: The arrow illusion of conscious intentionality as downward causation. Autores Barutta J, Gleichgerrcht E, Cornejo C, Ibanez A.  Año 2010 Journal  Barutta J, Gleichgerrcht E, Cornejo C, Ibanez A.  Volumen 44(2): 127-143 Abstract   Otra información